2001 Pontiac Trans Am - Silent Thunder

When I first slid behind the wheel of my 2001 WS-6 Trans Am, I was blown away. No other car that I have ever driven has had such a perfect balance of comfort, style, performance, and real-world usability. Not wishing to change a thing, I swore that the car was perfect and not one of the car's many bolts or nuts need ever be turned. But things change.

One of the things I wanted to test was one of the many aftermarket exhaust systems on the market for LS1-powered cars. B&B Performance Exhaust has one of the more popular systems on the market, and has kits available for both V6 and V8 cars, 1993 and newer. As builders of aftermarket systems for vehicles like BMW, Porsche, and Audi, B&B has quite a reputation, especially for their famed 3-into-1 Porsche header from which they coined the Tri-Flo name. Systems are also available for Impala SSs and '84 and later Vettes.

Before putting B&B's claims of improved F-body sound, horsepower, and style to the ultimate test, we needed to baseline the car's horsepower in showroom-stock condition, as well as perform the intake mods we wished to evaluate. We enlisted the help of Winter Performance for some runs on their DynoJet chassis dyno. Without a single modification, we saw best values of 308.3 horsepower and 319.4 ft.-lbs. of torque.

First, a Holley Powershot filter was added, which changed almost nothing: 309.0 horsepower and 318.7 ft-lb. of torque were the numbers. Normally, it's rare that a carmaker provides an adequately sized paper air filter on one of their vehicles, yet that seems to be the case here. Note, however, that more highly modified vehicles would surely overwhelm the paper unit's airflow capabilities and benefit from the Holley. Also, paper filters take a real hit in flow when dirty, whereas the Holley suffers only slightly. Next, an LS1 Motorsports Direct-Flo airlid was slipped on, and we saw some real progress, to the tune of 316.2 horses and 328.2 ft-lb. (see sidebar).

With the intake system addressed to our satisfaction, it was time to install the B&B exhaust and hope for an even further improvement. Gary's Service Center graciously let us use their lift-which was only needed for photography purposes, as you can easily do this job on floor jacks. We were in and out in about 40 minutes, including taking time for pictures. Getting the original WS-6 system off of the car was the hardest part, but even that was easy. Once that was out of the way, the B&B system literally slipped together and, it seems, could not have been manufactured any better.

The one and only problem that we encountered with the B&B was that the driver's side tailpipe was exactly one inch longer than the passenger's side, making it stick out further. You had to look closely to see this, but it was obvious when viewing the rear of the car from certain angles. This condition was remedied simply by trimming the right amount off the muffler-mounted driver's side pipe with a sawzall.

Upon lowering the lift for the final time, I turned the WS-6's ignition key and was greeted by a somewhat more distinct snarl that should have been there to begin with. Although a lot quieter than I expected initially, the exhaust note proceeded to get significantly more pronounced the more I drove the car. It now sounds, I think, just perfect. With a quiet cruise and a very sophisticated raspiness that builds as the RPMs climb, there is now worthy sound to complement the T/A's this-thing-means-business style. And there is no increase in interior noise whatsoever, much less any interior resonance. "Silent thunder" is perhaps the best term to describe it.